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COVID-19/SARS-CoV-2: Infection, Vaccination and Immune Response

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A special issue of Microorganisms (ISSN 2076-2607). This special issue belongs to the section "Virology".

Deadline for manuscript submissions: closed (20 October 2023) | Viewed by 11057

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Special Issue Editor

Dr. Athanasios G Michos

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Guest Editor

First Department of Paediatrics, Infectious Diseases and Chemotherapy Research Laboratory, Medical School, National and Kapodistrian University of Athens, “Aghia Sophia” Children’s Hospital, 11527 Athens, Greece
Interests: pediatric infectious diseases; molecular microbiology; diagnostics; immunology and pathogenesis of infectious diseases; vaccines
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

It has been almost three years combating COVID-19, and still, major aspects of the immune response following vaccination and/or infection remain to be fully understood. Multiple vaccines have been developed which effectively slowed the pandemic, which is encouraging; however, emerging variants have compromised the efficacy of available vaccines and made it necessary to develop new vaccines. Current research has, therefore, focused on the development of both new variant-specific and pan-coronaviral vaccines. Apart from vaccines, the efficacy of therapeutic antibodies has also been influenced in the face of evolving variants, which requires the development of variant-resistant broadly neutralizing antibodies and other therapeutic agents.

Immunity acquired through vaccination or infection naturally weakens with time, which further increases the risk of infections or re-infections. Although much research has been conducted in a relatively short span of time, a clear understanding of the detailed immune response is still needed.

For this Special Issue, we invite contributions that focus on the advancement of our understanding of SARS-CoV-2 infections, the immunological responses, and new vaccine strategies. Original research articles and reviews are welcome.

Dr. Athanasios G Michos
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Microorganisms is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

SARS-CoV-2 infections
immunological responses
new vaccine strategies

Published Papers (7 papers)

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Research

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13 pages, 1713 KiB

Open AccessArticle

Epidemiology of the SARS-CoV-2 Omicron Variant Emergence in the Southeast Brazilian Population

by Evandra Strazza Rodrigues, Svetoslav Nanev Slavov, Debora Glenda Lima de La Roque, Elaine Vieira Santos, Josiane Serrano Borges, Mariane Evaristo, Péricles Natan Mendes da Costa, Juliana de Matos Maçonetto, Adriana Aparecida Marques, Anemarie Dinarte Baccarin, Renata Aparecida Machado Oliveira, Wilson Lau Junior, Bruno Iglesias Benincasa, Luana Martins de Andrade da Cruz, Alex Ranieri Jerônimo Lima, Gabriela Ribeiro, Vincent Louis Viala, Loyze Paola Oliveira de Lima, Antonio Jorge Martins, Claudia Renata dos Santos Barros, Elaine Cristina Marqueze, Jardelina de Souza Todao Bernardino, Rejane Maria Tommasini Grotto, Jayme A. Souza-Neto, Vagner Fonseca, Maurício Lacerda Nogueira, Heidge Fukumasu, Luiz Lehmann Coutinho, Rodrigo Tocantins Calado, Dimas Tadeu Covas, Marta Giovanetti, Luiz Carlos Junior Alcantara, Sandra Coccuzzo Sampaio, Maria Carolina Elias and Simone Kashima Show full author list Hide full author list

Microorganisms 2024, 12(3), 449; https://doi.org/10.3390/microorganisms12030449 - 23 Feb 2024

Viewed by 882

Abstract

The aim of this study was to describe epidemiological characteristics and perform SARS-CoV-2 genomic surveillance in the southeastern region of São Paulo State. During the first months of 2022, we compared weekly SARS-CoV-2 infection prevalence considering age, Ct value, and variants’ lineages. An increase in the number of SARS-CoV-2-positive cases until the fourth epidemiological week of 2022 was observed. From the fourth epidemiological week onwards, the number of tests for SARS-CoV-2 diagnosis began to decrease, but the number of positive samples for SARS-CoV-2 remained high, reaching its most expressive level with a rate of 60% of infected individual cases. In this period, we observed a progressive increase in SARS-CoV-2 infection within the 0–10 age group throughout the epidemiological weeks, from 2.8% in the first epidemiological week to 9.2% in the eighth epidemiological week of 2022. We further observed significantly higher Ct values within younger patient samples compared to other older age groups. According to lineage assignment, SARS-CoV-2 (BA.1) was the most prevalent (74.5%) in the younger group, followed by BA.1.1 (23%), BA.2 (1.7%), and Delta (1%). Phylogenetic analysis showed that BA.2 sequences clustered together, indicating sustained transmission of this Omicron VOC sub-lineage by that time. Our results suggest the initial dissemination steps of the Omicron’s sub-linage BA.2 into the younger group, due to specific genomic features of the detected sequences. These data provide interesting results related to the spread, emergence, and evolution of the Omicron variant in the southeast Brazilian population. Full article

(This article belongs to the Special Issue COVID-19/SARS-CoV-2: Infection, Vaccination and Immune Response)

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9 pages, 918 KiB

Open AccessCommunication

In Vitro and In Vivo Crosstalk between Type I IFN and IL-8 Responses in SARS-CoV-2 Infection

by Mirella Biava, Stefania Notari, Germana Grassi, Licia Bordi, Eleonora Tartaglia, Chiara Agrati, Eleonora Cimini, Giuseppe Sberna, Emanuele Nicastri, Andrea Antinori, Enrico Girardi, Francesco Vaia, Fabrizio Maggi and Eleonora Lalle

Microorganisms 2023, 11(11), 2787; https://doi.org/10.3390/microorganisms11112787 - 16 Nov 2023

Viewed by 752

Abstract

COVID-19 patients show characteristic over-expression of different cytokines that may interfere with the interferon (IFN) response, delaying its production. Within the overexpressed cytokines, IL-8 plays a key role, and it may impede IFN-I activation. PBMC from eight healthy donors were exposed to 2019-nCoV/Italy-INMI1 isolate and supernatants/cells were collected at different time points; the production of either IFN-alpha or IL-8 was assessed. The same analysis was performed on plasma samples obtained from 87 COVID-19 patients. Antagonism between IFN-alpha and IL-8 was observed, since in those PBMC with medium or high IL-8 levels, IFN-α levels were low. The same scenario was observed in SARS-CoV-2-infected patients that were divided into three groups based on IL-8 low, medium and high levels; the correlation between low levels of IFN-α and high levels of IL-8 was statistically significant in both the IL-8 medium and IL-8 high group. Overall, our results showed a crosstalk/antagonism between IL-8 and IFN-alpha in PBMC from healthy donors challenged with SARS-CoV-2 and inversely proportional IFN-alpha levels to IL-8 concentrations detected in plasma samples from COVID-19 patients, suggesting that the impairment of the innate immune response in COVID-19 patients may be linked to a dysregulated cytokine response, namely through IL-8 production. Full article

(This article belongs to the Special Issue COVID-19/SARS-CoV-2: Infection, Vaccination and Immune Response)

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12 pages, 1442 KiB

Open AccessArticle

High Levels of IL-1β, TNF-α and MIP-1α One Month after the Onset of the Acute SARS-CoV-2 Infection, Predictors of Post COVID-19 in Hospitalized Patients

by Jacobo Alonso-Domínguez, María Gallego-Rodríguez, Inés Martínez-Barros, Beatriz Calderón-Cruz, Virginia Leiro-Fernández, Alexandre Pérez-González and Eva Poveda

Microorganisms 2023, 11(10), 2396; https://doi.org/10.3390/microorganisms11102396 - 26 Sep 2023

Cited by 1 | Viewed by 1447

Abstract

The pandemic caused by SARS-CoV-2 infection has left behind a new symptomatology called post COVID-19, or “long COVID”. The pathophysiological mechanisms still remain controversial; however, a link between persistent inflammation and these sequelae has been suggested. Herein, we longitudinally assessed up- and downstream molecules of the NLRP3 inflammasome’s pathway in three study groups: healthy donors (HC, n = 14) and donors with a confirmed SARS-CoV-2 infection who had been hospitalized, the latter divided into post COVID-19 (PC, n = 27) and non-post COVID-19 patients (nPC, n = 27) based on the presence or absence of symptomatology at month 6, respectively. Plasma cytokines (IL-1β, IL-3, IL-6, IL-8, IL-18, IP-10, MIG, TNF-α, IFN-γ, MIP-1α and MIP-1β) and total peroxide (TPX) levels were quantified at baseline and at months 1 and 6 after the onset of the infection. Baseline values were the highest for both TPX and cytokines that progressively decreased thereafter the acute infection. IL-1β, MIP-1α and TNF-α at month 1 were the only cytokines that showed a significant difference between nPC and PC. These findings suggest that a persistent inflammatory state one month after the onset of SARS-CoV-2 infection related to specific cytokines (IL-1β, MIP-1α, and TNF-α) might guide to predicting post COVID-19 symptomatology. Full article

(This article belongs to the Special Issue COVID-19/SARS-CoV-2: Infection, Vaccination and Immune Response)

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11 pages, 587 KiB

Open AccessArticle

Kinetics of SARS-CoV-2 Spike Antibodies after the Second and Third Dose of the BNT162b2 COVID-19 Vaccine and Association with Epidemiological Characteristics and Breakthrough Infection in a Cohort Study of Healthcare Workers

by Elizabeth-Barbara Tatsi, Filippos Filippatos, Charilaos Dellis, Maria-Myrto Dourdouna, Vasiliki Syriopoulou and Athanasios Michos

Microorganisms 2023, 11(8), 2010; https://doi.org/10.3390/microorganisms11082010 - 4 Aug 2023

Cited by 1 | Viewed by 1075

Abstract

To prospectively study the kinetics of immune responses after immunization with the BNT162b2 mRNA COVID-19 vaccine and their association with epidemiological parameters and breakthrough infection (BI), we measured total (TAbs-WT) and neutralizing antibodies against wild-type (NAbs-WT) and Omicron (NAbs-O) SARS-CoV-2 spike proteins in healthcare workers (HCWs) after the second (4 and 8 months) and third dose (1 and 8 months). Vaccinated HCWs (n = 486), with a median age (IQR) of 49 years (38–56), were included in this prospective cohort study. BI was observed 4 and 8 months after the second dose in 8/486 (1.6%) and 15/486 (3.1%) HCWs, respectively, and 1 and 8 months after the third dose in 17/486 (3.5%) and 152/486 (31.3%) HCWs, respectively. A comparison of immune responses 1 month after the third dose in vaccinated HCWs without a BI or with a BI in the next 7 months did not detect any statistically significant differences in the TAbs-WT (median (IQR): 16,611.0 (13,011.0) U/mL vs. 17,572.5 (14,501.0) U/mL, p = 0.529) and NAbs-WT (median (IQR): 96.5% (1.7) vs. 96.7% (1.9), p = 0.555). After infection, HCWs with a BI had significantly increased TAbs-WT levels at all time points compared to healthy HCWs. The findings of the present study indicate that antibody levels after three doses of the BNT162b2 vaccine are not directly associated with the possibility of a BI. Full article

(This article belongs to the Special Issue COVID-19/SARS-CoV-2: Infection, Vaccination and Immune Response)

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13 pages, 1452 KiB

Open AccessArticle

Redistribution and Activation of CD16brightCD56dim NK Cell Subset to Fight against Omicron Subvariant BA.2 after COVID-19 Vaccination

by Huiyun Peng, Tianxin Xiang, Fei Xu, Yuhuan Jiang, Lipeng Zhong, Yanqi Peng, Aiping Le, Wei Zhang and Yang Liu

Microorganisms 2023, 11(4), 940; https://doi.org/10.3390/microorganisms11040940 - 3 Apr 2023

Cited by 4 | Viewed by 1337

Abstract

With the alarming surge in COVID-19 cases globally, vaccination must be prioritised to achieve herd immunity. Immune dysfunction is detected in the majority of patients with COVID-19; however, it remains unclear whether the immune responses elicited by COVID-19 vaccination function against the Omicron subvariant BA.2. Of the 508 enrolled patients infected with Omicron BA.2, 102 were unvaccinated controls, and 406 were vaccinated. Despite the presence of clinical symptoms in both groups, vaccination led to a significant decline in nausea or vomiting, abdominal pain, headache, pulmonary infection, and overall clinical symptoms and a moderate rise in body temperature. The individuals infected with Omicron BA.2 were also characterised by a mild increase in both serum pro- and anti-inflammatory cytokine levels after vaccination. There were no significant differences or trend changes between T- and B-lymphocyte subsets; however, a significant expansion of NK lymphocytes in COVID-19-vaccinated patients was observed. Moreover, the most effective CD16^brightCD56^dim subsets of NK cells showed increased functional capacities, as evidenced by a significantly greater IFN-γ secretion and a stronger cytotoxic potential in the patients infected with Omicron BA.2 after vaccination. Collectively, these results suggest that COVID-19 vaccination interventions promote the redistribution and activation of CD16^brightCD56^dim NK cell subsets against viral infections and that they could facilitate the clinical management of patients infected with Omicron BA.2. Full article

(This article belongs to the Special Issue COVID-19/SARS-CoV-2: Infection, Vaccination and Immune Response)

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11 pages, 1714 KiB

Open AccessArticle

Omicron Sub-Lineage BA.5 and Recombinant XBB Evasion from Antibody Neutralisation in BNT162b2 Vaccine Recipients

by Martina Brandolini, Giulia Gatti, Laura Grumiro, Silvia Zannoli, Valentina Arfilli, Monica Cricca, Giorgio Dirani, Agnese Denicolò, Maria Michela Marino, Martina Manera, Andrea Mancini, Francesca Taddei, Simona Semprini and Vittorio Sambri

Microorganisms 2023, 11(1), 191; https://doi.org/10.3390/microorganisms11010191 - 12 Jan 2023

Cited by 4 | Viewed by 1872

Abstract

The recent emergence of a number of new SARS-CoV-2 variants resulting from recombination between two distinct parental lineages or sub-lineages within the same lineage has sparked the debate regarding potential enhanced viral infectivity and immune escape. Among these, XBB, recombinant of BA.2.10 and BA.2.75, has caused major concern in some countries due to its rapid increase in prevalence. In this study, we tested XBB escape capacity from mRNA-vaccine-induced (BNT162b2) neutralising antibodies compared to B.1 ancestral lineage and another co-circulating variant (B.1.1.529 BA.5) by analysing sera collected 30 days after the second dose in 92 healthcare workers. Our data highlighted an enhanced and statistically significant immune escape ability of the XBB recombinant. Although these are preliminary results, this study highlights the importance of immune escape monitoring of new and forthcoming variants and of the reformulation of existing vaccines. Full article

(This article belongs to the Special Issue COVID-19/SARS-CoV-2: Infection, Vaccination and Immune Response)

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Review

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16 pages, 777 KiB

Open AccessReview

Long COVID-19 Pathophysiology: What Do We Know So Far?

by Nikolaos-Renatos Tziolos, Petros Ioannou, Stella Baliou and Diamantis P. Kofteridis

Microorganisms 2023, 11(10), 2458; https://doi.org/10.3390/microorganisms11102458 - 30 Sep 2023

Cited by 5 | Viewed by 2799

Abstract

Long COVID-19 is a recognized entity that affects millions of people worldwide. Its broad clinical symptoms include thrombotic events, brain fog, myocarditis, shortness of breath, fatigue, muscle pains, and others. Due to the binding of the virus with ACE-2 receptors, expressed in many organs, it can potentially affect any system; however, it most often affects the cardiovascular, central nervous, respiratory, and immune systems. Age, high body mass index, female sex, previous hospitalization, and smoking are some of its risk factors. Despite great efforts to define its pathophysiology, gaps remain to be explained. The main mechanisms described in the literature involve viral persistence, hypercoagulopathy, immune dysregulation, autoimmunity, hyperinflammation, or a combination of these. The exact mechanisms may differ from system to system, but some share the same pathways. This review aims to describe the most prevalent pathophysiological pathways explaining this syndrome. Full article

(This article belongs to the Special Issue COVID-19/SARS-CoV-2: Infection, Vaccination and Immune Response)

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